Design and development of a microfluidic-based platform, combined with fluorescent gold nanoclusters for cyanide detection in blood

Cyanide can be found in many household foods and products, as well as the combustion products of many synthetic materials, especially used in industry. The distinction between poisoning from carbon monoxide (CO) and hydrogen cyanide (HCN) caused by the burning of cyanide-containing compounds, especially in many industrial or household fires, is not easily to detect. Due to difficulties in diagnosis and application of treatment related to the detection on time, many casualties may occur as described in literature. Many toxic effects occur as a result of oral intake, inhalation and absorption of cyanidecontaining substances. Because of the half-life of cyanide is short, the rate of diagnosis for treatment has also a great importance. There are currently blood and urine-based cyanide determination methods, but they are insufficient in terms of both sample storage and transportation, cost and analysis times. For this reason, there is a need for a system that will allow rapid diagnosis of cyanide from the exposed person and to measure the concentration of exposed cyanide level. A cost-effective and rapid microfluidic platform for colorimetric cyanide detection in human whole blood plasma based on quenching effect of fluorescent gold nanoclusters (AuNCs) in the presence of cyanide has been designed and developed within the scope of the thesis. Elsner reaction between AuNCs and cyanide provides high selectivity in contrast to other metal ions and salts. A microfluidic multi layer compact disc (CD) with 200 μm and 500 μm channels and an Arduino Uno based portable centrifuge device which has rotational speed range between 500 RPM and 5000 RPM for rapid plasma seperation from whole human blood were also designed and developed in this study. A software for controlling the rotational speed of CD was also developed. With the help of a smart phone and a mobile application which is free for commercial and non-commercial use we represent a novel colorimetric method for detection of cyanide in human blood plasma. The system can detect cyanide in human blood plasma in the concentration range between 0,1 mg/L and 5 mg/L which is described safe and dangerous interval in the literature. We believe that a highly selective, rapid and cost effective AuNCs based centrifugal microfluidic cyanide detection system in human blood plasma which is reported in this study can be an alternative to conventional cyanide detection systems.